The invention relates in general to indirect fire weapons and in particular to muzzle brakes for indirect fire weapons.
Muzzle brakes for large caliber indirect fire weapons have been used to reduce recoil energy of the cannon system, thereby allowing the overall weapon system to be reduced in weight. This weight reduction of the system may increase the system transportability by air and land. The M119A2 105 mm howitzer is an example of an indirect fire system that utilizes a muzzle brake for this reason. The M119A2 105 mm howitzer may be transported by a Chinook or UH-60 Black Hawk helicopter. The M119A2 cannon system, known as the M20A1, utilizes a single-baffled brake in its design. The M777 155 mm howitzer system is another system that utilizes a muzzle brake for recoil reduction. The M777 155 mm howitzer system may be transported by MV-22 Osprey, CH-47 helicopter or by truck.
When muzzle brakes are used, propellant gas may be redirected rearward to reduce the recoil energy of the cannon. The incidence of this propellant gas upon the cannon crew may have a direct negative effect on the crew that is manning the cannon. The negative effect of the rearward directed gas is called blast overpressure (BOP). BOP may severely cripple a crew manning a cannon. When the crew is exposed to high BOP levels, they may face several dangers from the blast wave, including significant hearing damage and damage to other body organs. The U.S. Department of Defense uses the MIL-STD-1474D standard to determine if BOP (also known as impulse noise) is too dangerous for the crew, as well as to determine permissible exposure levels per day. Since the inception of muzzle brake technologies, the negative effect of BOP has plagued designers.
In the design of muzzle brakes, it may be desirable to maximize recoil reduction while minimizing the BOP that may be produced. A long-felt and unsolved need exists for a muzzle brake that may generate lower BOP than known muzzle brakes, while still providing adequate recoil reduction.